► This thesis presents a Dynamic Adjustment in Handover Thresholds (DAHT) for off-loading in LTE small cells. The proposed DAHT can distinguish whether an User Equipment…
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▼ This thesis presents a Dynamic Adjustment in Handover Thresholds (DAHT) for off-loading in LTE small cells. The proposed DAHT can distinguish whether an User Equipment (UE) is in static or mobile status. Additionally, DAHT can off-load Evolved Node B (eNB) by calculating a Handover Factor (HF). Based on the HF, source eNB can decrease or increase the offset of Reference Signal Receiving Power (RSRP) between source eNB and target eNB. Therefore, source eNB can advance or delay handover of UE to target eNB. In order to implement the proposed DAHT, we design the load measurement module on eNB to periodically measure and report the load of eNB, and design UE handover module on eNB to advance or delay UEâs handover. Moreover, we design load status module on Self-Organizing Network (SON) of Evolved Packet Core (EPC) to classify the load status of an eNB (i.e., heavy, medium, and low). Finally, we design offloading module on SON to calculate the off-loading amount. To validate the superiority of the proposed DAHT, we implement the aforementioned modules on ITRIâs (Industrial Technology Research Institute) small cell platform. During the experiment, we measure the load status of eNB and the residence time of UE to prove that the proposed DAHT can achieve advance or delay handover.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Tsung-Chuan Huang (chair), Zi-Tsan Chou (chair), Chung-Nan Lee (chair).

► Adding a relay station (RS) to form a multi-hop network can reduce the transmission distance which naturally improves channel quality. In video streaming on a…
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▼ Adding a relay station (RS) to form a multi-hop network can reduce the transmission distance which naturally improves channel quality. In video streaming on a multicast tree, BS conventionally chooses a modulation and coding scheme (MCS) to cope with a link with the worst channel quality. Although this conservative approach can guarantee the accuracy of data transfer, it adversely sacrifices the system throughput because it loses the opportunity for choosing a better MCS. Most of the previous researches focused on how to determine a suitable MCS according to channel quality, but they ignored that different users may have different requirements for video quality. To remedy this problem, in this thesis, we first propose three types of adaptive MCS for a multicast network with a tree structure: (1) WMPT (Worst Modulation per Tree), (2) WMPH (Worst Modulation per Hop), and (3) ISMM (In-Sequence Multiple Multicasting). WMPT chooses the worst modulation among all links in a tree to do multicasting. WMPH chooses the worst modulation among all links in each hop to do multicasting. ISMM uses multiple multicast trees in a sequence according to the channel quality of the transmission path. MATLAB simulation is performed to compare the performance of the three different types of adaptive MCS. Simulation results show that although ISMM may exhibit higher end-to-end delay than WMPT and WMPH, it can significantly increase the throughput of overall system. Finally, in ISMM, we come up with mathematical equations to compute the extra delay required at every relay station.
Advisors/Committee Members: Zi-Tsan Chou (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Chungnan Lee (chair).

► In a RFID system, how to avoid collisions among tags is an important factor to reduce readerâs identification time. From the survey of recent control…
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▼ In a RFID system, how to avoid collisions among tags is an important factor to reduce readerâs identification time. From the survey of recent control methods, none of them could make reader amplify or reduce power to avoid the collisions. To solve the collision problem, we propose a Dynamic Power Adjustment (DPA) scheme for reader. The proposed DPA can reduce identification time by raising or lowering the transmission power of a reader. DPA uses TDMA frames to read tagâs identification code. There are three cases in a TDMA slot; the state of successfully reading identification number, the state of collision, and the state of idle. We calculate the factors of adjusting power based on the three states, and then compute the power differences from the factors to adjust power. Computing the power differences considers two aspects: one is if the number of idle state in a frame far exceeds the number of collision state, reader will be increased power to read more tags, another one is if the number of idle state in a frame is much smaller than the number of collision state, reader will be cut power to reduce the number of tagâs reading. Finally, we use NS-2 to simulate the proposed DPA. In the simulation. We design three different topologies which place tags in three distributions, even, random, and hot-spot, respectively. From the simulation results, we validate the proposed DPA by demonstrating that it takes much less time in completing the identification of all tags, particularly when tags are placed in hot-spot distribution.
Key Wordsï¼RFID, Reader, Tag, DPA, TDMA, Frame, Slot, NS-2
Advisors/Committee Members: Zi-Tsan Chou (chair), Chungnan Lee (chair), ling%20Sheu%22%29&pagesize-30">Tsang-lingSheu (committee member).

▼ This thesis describes the design and evaluation of an integrated circuit (ASIC) implement eight parallel signal channels providing analog-amplitude delay-and-add functionality. This implementation is a fundamental building block towards the future realization of a low-power velocity-selective-recording arrangement (VSR) for the processing of the peripheral neurogram. The system is intended to operate with preamplified nerve signals acquired in the true-tripole configuration using an implanted nerve cuff. The matched velocity and sample rate are controlled by externally supplied digital clocks. The ASIC contains the clock phase generators (which use the suppliedclocks as reference), four capacitance-based sample-and-hold sections each consisting of eight sampling cells with summation functionality, an output buffer, and supporting control units. The circuits were fabricated in TSMC 0.35 Î¼m CMOS technology. Two slightly different versions of the integrated system are reported. The second version adds an on-chip frequency divider to achieve more finely controlled sample settings and it improves the layout. The active area is about 850 Î¼m*450 Î¼m and 640 Î¼m*390 Î¼m respectively. Both systems are evaluated in transistor-level simulation. Moreover, bench test measured results for the second version system are presented which confirm the correct operation of the on-chip generated timing signals and a measured power consumption of 170 Î¼W using a 3.3V supply.
Advisors/Committee Members: Ching-Hsing Luo (chair), Robert Rieger (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► The analog-to-digital converter (ADC) is an essential component in modern mixed-signal system applications. This thesis presents the design and evaluation of a single-slope integrating ADC…
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▼ The analog-to-digital converter (ADC) is an essential component in modern mixed-signal system applications. This thesis presents the design and evaluation of a single-slope integrating ADC which features medium-resolution, medium-speed and low-power-consumption, suitable for application in a bio-signal acquisition front-end. The aim of this study is to simplify the external control signals and to reduce the power consumption of the analog part of the converter compared to previously reported single-slope integrating ADC. For practical evaluation the design was realized as a prototype in TSMC 1P6M 0.18Î¼m CMOS technology proving 10 bit resolution. The measured power consumption is 18 Î¼W when operating with 40 kHz sample-rate and the chip active area occupies 0.06 mm2
Advisors/Committee Members: Tong-Yu Hsieh (chair), Jia-Jin Chen (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Robert Rieger (committee member).

► In the application of wireless sensor networks (WSNs), localization/positioning of sensor nodes is one of the key technologies. We need to know the event location…
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▼ In the application of wireless sensor networks (WSNs), localization/positioning of sensor nodes is one of the key technologies. We need to know the event location in many applications such as environmental observation, fire detection, object tracking, and military monitoring; otherwise it is useless even the event was detected. It is a good way to get the coordinate of sensor nodes by using GPS (Global Positioning System). However, equipping GPS for each sensor node will consume more energy and increase more costs[3,4]. Some researchers[6-8] present a solution to overcome this problem. They use mobile anchors that are equipped with GPS to help all the sensor nodes to locate. The mobile anchors move along the sensing area and broadcast the position information periodically. A mobile anchor can be treated as a replacement of plenty of static sensors that are equipped with GPS, greatly reducing the cost of sensor positioning.
The path planning of mobile anchors can be either static or dynamic[12,19,20]. A static path is decided before any localization action; however, a dynamic path is determined in real-time based on the real distribution of sensors nodes. Li et al. presented a dynamic path planning method of mobile anchor called SPNP[17]. The mobile anchor decides the next position according to the amount of neighbors of sensor nodes whose positions are known roughly in mobile anchorâs communication range. The neighbors of sensor nodes include localized and unknown. But actually, localized neighbors do not need the help of anchor to localize. In this paper, we improved SPNP by dividing anchor's communication range into six regions and calculate the amount of unknown sensors in each region. The localized sensors are not taken into account. Simulation results show that compared to SPNP, the mobile anchor can increase the percentage of localized sensors and localize them effectively.
Advisors/Committee Members: Ze-Sheng Chen (chair), Ming-Shi Wang (chair), Tsung-Chuan Huang (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► In recent years, mobile positioning services are increasingly used for many applications with the growing popularity of smart mobile devices. Wi-Fi indoor positioning has become…
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▼ In recent years, mobile positioning services are increasingly used for many applications with the growing popularity of smart mobile devices. Wi-Fi indoor positioning has become a research focus due to the popularity of Wi-Fi and no-additional hardware cost. Although active researches have been conducted on received signal strength (RSS) fingerprint-based indoor position, most of the current systems hardly overcome the costly and time-consuming offline training phase. For improving this problem, Bahl et al. [1] proposed a model-based indoor positioning system, which constructed a theoretically-computed radio map by using the radio propagation model. Although the accuracy is lower than other systems, less overhead to deploy is its advantage.
On the other hand, smartphones integrate various kinds of inertial sensors such as accelerometer, magnetometer, gyroscope, etc. In this thesis, we utilize them to detect user movements and implement an indoor positioning system. This system is based on the prototype of Bahlâs model-based system and uses two mechanisms to improve its accuracy. Firstly, it tracks user's walk path with inertial sensors on the smartphone to assist positioning. Secondly, the collected data is used to update the radio map and improve its accuracy.
We implement this system on Android smartphone and evaluate the performance. The experiment of results show that our system gets better accuracy than original model-based positioning system.
Advisors/Committee Members: Tsung-Chuan Huang (committee member), Ming-Shi Wang (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Ze-Sheng Chen (chair).

► This thesis consists of two subjects of research: A Digital Modulation bit error rate study for transmission using the human body as the transmission channel,…
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▼ This thesis consists of two subjects of research: A Digital Modulation bit error rate study for transmission using the human body as the transmission channel, and signal coupling using a piezo transducer.
The first topic involves studying several kinds of Digital Modulation and application; the transceiver is implemented using LabView. The interface for transmission uses Piezo film transducers. A high pass filter is used to remove noise and interference. The bit error rate using Manchester-coding is measured. A brief discussion is presented justifying the choice of On-Off Keying (OOK) modulation to transmit data on the human body.
The second topic is a study on the design and implementation of a human body transmission system. A test chip is designed in TSMC 0.35Î¼m 2P4M CMOS process and first measured results are presented.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Jih-ching Chiu (chair), Robert Rieger (committee member), Jia-Jin Jason Chen (chair).

► In the research of the humanoid biped robot, for building a robot model with 18 dimensions and applying this model to achieve the balance of…
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▼ In the research of the humanoid biped robot, for building a robot model with 18 dimensions and applying this model to achieve the balance of robot behavior, it needs for large amount of calculation of mathematical derivations. The study on biped walking control using reinforcement learning is presented in this paper.
When the robot keeps balance to walk, the zero moment point (ZMP) position of a biped robot has to be considered. If the ZMP of a biped robot could be controlled in an ideal state, the robot would walk steadily on the plain, even when the robot walks on a slope. In the robot walking process, a robot is easy to fall down when standing with one leg. Therefore, the research topic is mainly focused on how the robot keeps balance with one leg. The balance control way that utilized the motion of robot arm and leg to transfer the ZMP of the robot would maintain the ZMP in a stable state. In addition, the balance control way also can simplify the complexity of control of many servo motors. In this paper, the agent learns to control the ZMP by some balance control experience of human walking. It not only enhances learning efficiency, but also enables the robot walking gait more like human behavior.
Furthermore, the proposed method integrates the balanced algorithm with the balance control way and is applied on biped walking on the plain or seesaw make the biped walk more stable. Finally, there are several simulations that demonstrate the feasibility and effectiveness of the proposed learning scheme. The Research results are presented by the video at YouTube: http://youtu.be/05a0hamjt9Q
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Yu-Jen Chen (committee member), Tsung-Chuan Huang (chair), Kao-Shing Hwang (committee member).

► As technology advances, the developmental pace of various industries is also advancing at an amazing rate. Manpower allocation appears to be relatively rare and important.…
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▼ As technology advances, the developmental pace of various industries is also advancing at an amazing rate. Manpower allocation appears to be relatively rare and important. While machines have become more and more powerful, they can do many complex works. It is a trend that machines replace manpower.
The purpose of this paper is to make humanoid robot remember different actions by means of emulation and then make it repeat the action. The system applies the concept of motion sensing technologyâthe Xbox360 Kinect is used as the motion sensing input device, and DARwIn-OP is used as the humanoid robot. In action
emulation, The Kinect captures the human skeleton joint movement and are then calculated to angles. The angles are converted by a formula into motor counts that can be used in DARwIn-OP. The motor counts corresponding to each joint are transferred to DARwIn-OP through a wireless network (Wi-Fi). The built-in function of DARwIn-OP then enables the humanoid robot to immediately imitate the user's actions. In action replay, a jittering problem occurred when the original data was processed. To increase action fluency, we proposed key-pose identification algorithm and grouping algorithm to reduce the data size and to minimize the error with the original data. Finally, in action memorization, we proposed similarity rate calculation formula. The value calculated allows DARwIn-OP to determine if the same action has existed in its database. The data storage space can therefore be reduced.
The Kinect application programs of this system run in OpenNI and NITE environments. NITE is the middleware that provides the skeleton tracking algorithms to identify the user and to draw the skeleton. OpenNI reads and processes the data captured by Kinect. The system is demonstrated by a play of âMemorization and Replay of Humanoid Robot Actions by Emulationâ on YouTube .
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Kao-Shing Hwang (committee member), Tsung-Chuan Huang (chair), Yu-Jen Chen (chair).

► The purpose of this thesis is based on reinforcement learning applied on the control of biped robotâs walking balance, and learning how to walk straightforward…
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▼ The purpose of this thesis is based on reinforcement learning applied on the control of biped robotâs walking balance, and learning how to walk straightforward with well balance without involving any related biped robot dynamic model knowledge. In order to make the biped robot to be employed in a real environment, we need to make a discrete action space within a continuous action domain. It has become an issue worth exploring, because continuous actions are more applicable to real environment than simple discrete action and could enhance the learning efficiency. And then we use reinforcement learning to transfer for knowledge and to learn how to transfer tasks from various sources to the right objectives and to adapt them to different terrain to reach balance.
On training the zero moment point (ZMP) of each pose in to a stable and well-balanced state by Q-learning. Therefore, to make the biped robot walk well-balanced and steadily in real environment, we designed a learning structure; The balance control way that utilized the motion of robot arm and leg to transfer the ZMP. Based convention Q-learning which can generate a mapping between a paradigm action and a discrete state space, the proposed reinforcement learning algorithm is developed to deal with the problem of reinforcement learning in continuous action domain by means of a self-organized mechanism .
In addition, this thesis also presents terrain coupling algorithm to convert different experiences, which is based on various different tasks and experiences applied to seesaw environment, with the purpose of making the robot move forward stably on a seesaw. Among them, the uphill, downhill, and flat ground walking experiences are viewed as our source task. The Research results are presented by the video at YouTube: http://youtu.be/mVahCHBFWyo
Advisors/Committee Members: Kao-Shing Huang (committee member), Tsung-Chuan Huang (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Yu-Jen Chen (chair).

► In the information age, various computers, smart phones and tablet computers provide diversified functions, each function has its own operating procedures, and it has become…
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▼ In the information age, various computers, smart phones and tablet computers provide diversified functions, each function has its own operating procedures, and it has become more complicated to use the computer for senior citizens. It is one of the reasons why senior citizens are unwilling to use the electronic products.
The purpose of this thesis is to develop a multimedia system with video communication for the senior citizens. The thesis designs a simple system with the digital TV that government try to carry out. The senior citizens would not have to change existing habits or learn additional operations to easily use the system.
The system integrates the Linphone video communication software, web browser video player based on the Gstreamer library and life photographs share. Through a simple interface operation, the senior citizens can comfortably watch movies or interact with their families in a digital way without much difficulty.
The system is implemented on the ARM-based TI Pandaboard platform. The system provides remote control methods through smart phone or Bluetooth wireless keyboard and mouse. Users can install the application on the smart phone as a remote control to operate all functions of the system. The demonstration can be seen in the video at onYouTube: http://youtu.be/nJwmMbl8i3U
Advisors/Committee Members: Tsung-Chuan Huang (chair), Kao-Shing Hwang (committee member), Yu-Jen Chen (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► In recent years, due to the development of computers and the Internet, the robotics industry has steadily grown. Besides academic applications, entertainment robots can also…
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▼ In recent years, due to the development of computers and the Internet, the robotics industry has steadily grown. Besides academic applications, entertainment robots can also be programed to bring us unprecedented performances that many people can enjoy. Robotic puppet shows are an important part of the entertainment robot field. The robot can integrate the basic ability to speak, make poses and human like expressions. Based on the considerations above, this thesis describes an Editorial Platform for Screenplay of Interactive Robotic Puppet Shows (EPFS). EPFS lets users in different age groups control robots and allows them to write the screenplays for drama performances in a simple and fast way. In the platform users have the ability to use game design concepts that allow them to make diverse screenplays and a multitude of different storylines. Finally, the platform controls and records the story-making process by constructing a timeline. In doing so, problems caused by robotic expression and interaction can be solved. In addition, the arrangement of screenplays will be more flexible and accurate. According to the results of the experiment the platform proves to be flexible and easy to use. A video presentation of the thesis has been posted on YouTube, please search the title belowâAn Editorial Platform for Screenplay of Interactive Roboticâ.
Advisors/Committee Members: Yu-Jen Chen (chair), Tsung-Chuan Huang (chair), Kao-Shing Hwang (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► In a wireless sensor network (WSN), sensors are generally battery-powered. Hence it is essential to design a good power saving protocol, which operates at the…
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▼ In a wireless sensor network (WSN), sensors are generally battery-powered. Hence it is essential to design a good power saving protocol, which operates at the medium access control (MAC) layer, to prolong the lifetime of a WSN. Recently, quorum systems are heavily utilized to design power saving protocols for a WSN where each senor wakes up in time frames associating with a quorum. In a quorum system, any two quorums always overlap. However, existing quorum-based power saving protocols are far from optimal in terms of duty cycle and configurability. Especially, we notice that in a corona-based WSN, there is no need to insist on the overlap of awake time frames between every pair of sensors. By only guaranteeing the overlap of awake time frames between sensors in neighboring coronas, the whole WSN can still function well since each sensor needs to rely on merely the sensors in the inner adjacent corona to forward data to the sink. On the basis of this principle, we design an optimal and maximized configurable power saving protocols, called Green-MAC, for a corona-based WSN. More specifically, given the maximum cycle length n_max, in Green MAC, the duty cycle of each sensor is only O(1 â n_max ), and the number of configurable duty cycles can be O(n_max â ln n_max ). These results reach the theoretically asymptotic optimum. To illuminate the power of configurability, we focus on the event detection and reporting applications, and show how to configure the cycle length for sensors in each corona such that the source-to-sink delay requirement can be satisfied with a predefined probability. Extensive simulation results demonstrate that Green-MAC is much superior to existing quorum-based power saving protocols in terms of throughput, lifetime, and data delay dropped ratio.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Fan-Shuo Tseng (chair), Kuo-Feng Chen (chair), Zi-Tsan Chou (committee member).

► Broadcasting is a common operation for disseminating traffic-related information in vehicular ad hoc networks (VANETs). However, broadcasting in wireless networks can easily cause the broadcast…
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▼ Broadcasting is a common operation for disseminating traffic-related information in vehicular ad hoc networks (VANETs). However, broadcasting in wireless networks can easily cause the broadcast storm problem especially in high vehicular density environment. Therefore, most of the broadcast storm suppression schemes aim to decrease the number of forwarders so as to reduce the redundant packet and mitigate the broadcast storm problem. One of the broadcast storm suppression techniques is the distance-based scheme [15] in which the relative distance between the sender and the receiver is used to decide whether to rebroadcast a message or not. However, this conventional distance-based scheme may cause the improper measurement problem called in this paper. So we propose the Limited Hop Number Weighted p-Persistence Broadcasting (LHNWpPB) to resolve this problem. The simulation results show the proposed broadcast storm suppression scheme can reduce the number of forwarders and also the redundant packets.
Advisors/Committee Members: Ting-Wei Hou (chair), Tsung-Chuan Huang (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Zi-Tsan Chou (chair).

► In this thesis, we propose an improved communication protocol between sensor nodes and the central processing nodes based on IEEE 802.15.4. More specifically, we take…
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▼ In this thesis, we propose an improved communication protocol between sensor nodes and the central processing nodes based on IEEE 802.15.4. More specifically, we take the advantage of the guarantee time slot mechanism in the IEEE 802.15.4 specification to design a real-time forecasting mechanism for the central processing node to decide which the sensor nodes have priorities (and in what order) to access the shared channel. The protocol is implemented in a simulation program where multiple sensors can only compete to acquire a shared channel for transmitting data to a central processing node by the slotted CSMA/CA mechanism. Various scenarios were simulated to study the effectiveness of the proposed protocol.
The simulation results indicate that, without the real-time forecasting mechanism for assigning priority, many sensor nodes waste excessive energy on long-term channel monitoring. With the proposed protocol, it appears from the simulation results that the power consumption among the sensor nodes is equalized. Moreover, the results show that the high-data-flow sensors consume much less power with the proposed protocol, and the overall packet loss rate of the system is much improved.
Advisors/Committee Members: Chung-Yao Kao (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Wei Kuang Lai (chair).

► Nowadays the increase in the use of mobile devices has greatly raised the probability of mutual interference between different communication systems. Mechanisms that resolve mutual…
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▼ Nowadays the increase in the use of mobile devices has greatly raised the probability of mutual interference between different communication systems. Mechanisms that resolve mutual interference usually result in more energy consumption of the mobile devices involved, especially in the case of co-channel interferences. On the other hand, the trend of miniaturizing the mobile devices and making them light enough to be wearable restricts the size of their power sources; as the result, minimizing power consumption becomes essential for prolonging the operation of such devices. Therefore, it is important to develop an interference rejection mechanism that does not cause excessive power consumption.
Based on the characteristics of the wireless communication channel and the causes interferences, in this thesis we propose a new frequency demodulation technique and a new power control mechanism that together allow the receivers to distinguish high-power interferences from the signals intended to be received, even when the interferences have similar artificial characteristics with those of the intended signals. The proposed technique is implemented in a simulation programs. The simulation results show that, by the proposed technique, even when the co-channel interferences have the same modulation characteristics with the intended signals, the bit error rate ( BER ) can remain less than 10% if the signal-to-interference ratio ( SIR ) is between -30dB to 20dB. At the same time, the power consumption remains low and it is not necessary to increase transmitting power level to resist the interferences. By minimizing power consumption on resisting interferences, this âlower-power interference rejectionâ technique allows personal mobile devices which have small power sources to have longer operational periods. In addition to power saving, the proposed technique does not require the base station to transmit power level control signals to the mobile devices ( for suppressing interferences ) . This characteristic allows the personal devices to have greater independence, longer life cycle, better privacy, and security.
Advisors/Committee Members: Chung-Yao Kao (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Wei-Kuang Lai (chair).

▼ Zone Routing Protocol (ZRP) is a typical hybrid routing protocol used in Mobile Ad Hoc Networks (MANETs). Due to combing the advantages of proactive and reactive routing protocol, ZRP has been extensively applied on the dynamic network environments. To reduce the broadcasting control overhead, Haas et al. incorporated gossiping into ZRP called GZRP. However, when there exist articulation points in the local zone, the performance of GZRP will be degraded. Therefore, a heuristic articulation point detection algorithm(APD) has been proposed by Cheng[18] to prevent the degradation. In this paper, we will analyze the APD algorithm, discuss the situations that the articulation points can not be detected, with respect to different network nodes density, and verify the results by simulation.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Tse-Sheng Chen (chair), Tsung-Chuan Huang (committee member).

► With the advent of large scale mobile ad-hoc networks, the routing protocol should be able to provide better scalability and performance with the change of…
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▼ With the advent of large scale mobile ad-hoc networks, the routing protocol should be able to provide better scalability and performance with the change of the network topology. The hybrid routing protocols combine the best features of proactive/table-driven routing protocol and reactive/on-demand routing protocol, thus have led to widespread use[3][10].
Hung proposed a hybrid routing protocol called Core Gateway Relay Routing Protocol (CG2R)[1]. In the first of this protocol, each node is identified the cell it belongs to by the process of cell formation, such that, within the cell, any two nodes are one hop away from each other. The nodes that belong to two or more cells are called gateways; the set of cells that a gateway belongs to is defined as a super cell. Through the procedure of core gateway determination, certain gateways are determined as the core gateway. As the result, the nodes other than the core gateway nodes are all one hop away from the nearest core gateway node. Thus, as long as a packet is sent to all core gateways, it can be sent to all nodes in the network by one additional forwarding.
In this thesis, we point out that it cannot be ensured that two nodes in a cell are always one hop away from each other, so the CG2R cannot work properly in all network topology. By analysis, we present two conditions of topology which ensure that the process of cell formation can operate normally. In addition, we investigate the control overhead and the change of topology in variant nodes moving speed as well as nodes density, respectively. The ratio of network topology that CG2R can perform correctly is also simulated.
Advisors/Committee Members: Tsung-Chuan Huang (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Tse-Sheng Chen (chair).

► In this thesis, we propose a small-cell embedded large-cell sectored network (SELSN) architecture. An SELSN can be divided into two regions, the sector and the…
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▼ In this thesis, we propose a small-cell embedded large-cell sectored network (SELSN) architecture. An SELSN can be divided into two regions, the sector and the small cell. We increase the total number of overall system channels by using fractional frequency reuse (FFR), and divide the bandwidth into two or three sections depending on whether the number of sectors is even or odd. In order to analyze the new-call (NC) blocking and handoff-call (HC) dropping probability of the proposed SELSN, we build a mathematical model of Markov chains. In the mathematical model, we derive the handoff rate from HC by the area and the boundary length where a mobile station (MS) stays, and the speed and the direction of an MS. Based on the handoff rate of HC, we derive the Markov chainâs transition matrix to obtain the probability of each state. Finally, we change the size of a small cellâs radius, the number of the sectors, and the speed of MS to analyze the NC blocking and the HC dropping probability. From the two probabilities, we obtain the average waiting time (AWT) of an MS and the throughput of the overall system.
Advisors/Committee Members: ling%20Sheu%22%29&pagesize-30">Tsang-lingSheu (committee member), Tsung-Chuan Huang (chair), Zi-Tsan Chou (chair), Chungnan Lee (chair).

► Multicast is an effective scheme to save network bandwidth when real-time multimedia streams are transmitted over a mobile communication network. Current researches lack of a…
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▼ Multicast is an effective scheme to save network bandwidth when real-time multimedia streams are transmitted over a mobile communication network. Current researches lack of a comprehensive rate control mechanism for a mobile environment, where signal interference and network congestion occur very easily. It is well known that packet loss due to signal interference, network congestion, or even user mobility, may bring about a critical deterioration in video quality. In this thesis, we propose a dynamic rate control mechanism (DRCM), with which severe packet loss due to interference or congestion in a mobile network can be reduced. In DRCM, a mobile station (MS) can distinguish between interference and congestion via measured block error rate (BLER) and congestion loss rate (CLR). To effectively decrease packet loss rate (PLR), a base station (BS) can adjust its sending rate by measuring round trip time (RTT) and the returned BLER from MS. Two mathematical equations are derived to reduce PLR when interference and congestion occurs individually. Furthermore, we combine the equations together for deriving a minimum data rate when interference and congestion occur simultaneously. To evaluate the performance of the proposed DRCM, we perform NS-3 simulation. In the simulation, we discuss the impact of interference, user mobility, and buffer size on PLR while an adequate sending rate is determined. Simulation results have shown that the proposed DRCM can decrease PLR significantly in a mobile communication network.
Advisors/Committee Members: Zi-Tsan Chou (chair), Chungnan Lee (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Tsung-Chuan Huang (chair).

► In an LTE-A network, the traditional AMC scheme allocates RB based on SNR/CQI table reported from UE and the data rate requirement of UE. However,…
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▼ In an LTE-A network, the traditional AMC scheme allocates RB based on SNR/CQI table reported from UE and the data rate requirement of UE. However, this scheme will lead to allocating RB which is beyond the requirement of UE. To solve the problem, this thesis proposes a dynamic RB allocation scheme by utilizing ARQ status report in which UE reports erroneous packet with sequence number to eNodeB. From the status report, eNodeB will compute the amount of successfully received data per unit time of each UE. Therefore, eNodeB can properly allocate RB which is exactly the requirment of each UE. Moreover, in this thesis, we consider three traffic types (audio, video, and data) with different priorities. Our proposed scheme can alter the modulation determined by AMC such that the utilization of an OFDMA frame can be tremendously increased. To prevent the starvation of data traffic which has the lowest priority, we set an upper bound of occupied RB for audio and video traffic in an OFDMA frame. At last, we perform NS-3 simulation to demonstrate the superiority of the proposed scheme. The simulation results show that our proposed scheme can perform much better than the traditional AMC scheme in terms of system utilization, blocking rate of UEs, and the number of successfully connected UEs. Particularly, when in a high noise environment and a large number of UE, the proposed scheme can guarantee a smaller blocking rate for video traffic.
Advisors/Committee Members: Chungnan Lee (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Tsung-Chuan Huang (chair), Zi-Tsan Chou (chair).

► Controlling the robots through a robotic platform has recently been used widely; however, it is necessary to make the platform friendlier in use to bring…
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▼ Controlling the robots through a robotic platform has recently been used widely; however, it is necessary to make the platform friendlier in use to bring this product deeply into the family. The screenplay based performance platform (SBPP) of robotic puppet shows proposed in this thesis is a robotic platform composed with cloud computing, User Interface (UI) and Screenplay Interpreter(SI). The users can connect to the UI to edit and setup the screenplay ubiquitously through any device which can link to the internet. Through screenplay interpreter, the robot can perform as the designed screenplay after the setup; that is, one can always designate a different robot to execute during the process of editing, and the actions of these robots will be a message communication with preset meaning. The project of SBPP is divided into two modules: the UI and SI for multi-morphic robots. The work of this thesis takes charge mainly of screenplay interpreter for a variety of robot models and interfacing between NAO(pronounced now) which is a humanoid robot and the screenplay interpreter. And we integrate UI and SI. The integration of the work provides users a friendly UI to edit scenario of NAO and DARwIn-OP such the robot, NAO and DARwIn-OP(Dynamic Anthropomorphic Robot with Intelligence - Open Platform), can play in a scenario as the screenplay describing. The system is demonstrated by a play of âdo-as-I-doâ and recorded in a video at YouTube, http://www.youtube.com/watch?v=v8ErTOgAQSo.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Yu-Jen Chen (chair), Kao-Shing Hwang (committee member), Tsung-Chuan Huang (chair).

► With the development of the network, people are increasingly used to exchanging information on the Internet. Therefore, the capability of robot controller should not be…
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▼ With the development of the network, people are increasingly used to exchanging information on the Internet. Therefore, the capability of robot controller
should not be limited to control robots locally. The objective of this thesis is to provide a system, the screenplay based performance platform of Robotic puppet shows (SBPP), commanding multiple robots; each robot performing its own role based on a script composed by the developed authoring tool. Wherever and whenever a user wants to use SBPP, he/she just needs connect to the network and begins to design a script. SBPP consists of three parts: the graphic authoring platform (GAP) of screenplays for robotic puppet shows, the screenplay interpreter (SI) for
multi-morphic robots, and robots themself. The work of this thesis is concentrated on the implementation of the GAP and robots (model: DARwIn-OP) control. The GAP provides options for a variety of robots to users. The users can easily design their own robot scripts merely by drag-and-drop operating on icons representing the actions, behavior, and short scripts, respectively. Whenever a script is created or updated, GAP will automatically save the script as an XML file format internally. In addition, robots can be conducted to express their emotions orally by utter the lines composed. The system is demonstrated by a play of âdo-as-I-doâ and recoded in a video at YouTube:â
http://www.youtube.com/watch?v=v8ErTOgAQSoâ.
Advisors/Committee Members: Tsung-Chuan Huang (chair), Kao-Shing Hwang (committee member), Yu-Jen Chen (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► The objective of the thesis is utilizing body sensing technology to develop a more intuitive and convenient way to control robots. The idea is to…
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▼ The objective of the thesis is utilizing body sensing technology to develop a more intuitive and convenient way to control robots. The idea is to build a body sensing control system based on Kinect framework. Through Kinect, users from different age groups can achieve the desired purposes through motion demonstration without complicated programming. The system can accurately calculate angle change from usersâ gestures in a motion and identify key-postures which can compose an emulation motion similar to the presenting one. In other words, from analyzing these key postures, the demonstrated behaviors are able to be represented internally. Therefore, the system, consisting of a kinematics computational module and a representation algorithm, not only provides the function of behavior emulation but also behavior representation. By representation algorithm, the system extracts the features of combined behaviors. Besides, with the modular programming methodology, different behaviors can be reorganized to generate new behaviors based on the set of key poses represented by the extracted features. The application implemented in this system is within the OpenNI and NITE environment. OpenNI is used to retrieve information that the Kinect captured. NITE is used to track the user skeleton. The system is demonstrated by a play of âTai-Ji-Advancerâ and at http://www.youtube.com/watch?v=cSYS49JKVAA.
Advisors/Committee Members: Tsung-Chuan Huang (chair), Kao-Shing Hwang (committee member), Yu-Jen Chen (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

► In this thesis, we address the issue of routing on a cognitive ad hoc network, where all secondary users are mobile stations. Based on whether…
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▼ In this thesis, we address the issue of routing on a cognitive ad hoc network, where all secondary users are mobile stations. Based on whether mobile stations are equipped with GPS (global positioning system), routing protocols in a cognitive ad hoc network can be classified into two categories: location-free and location-aided. Location-free routing protocols typically employ flooding to find out the optimal routing path. One of the drawbacks of location-free routing protocols is that the data packets always travel through the fixed path even though the activities of primary users near to some mobile stations on the routing path become more frequent. Instead of using flooding, location-aided routing can adopt the greedy-forwarding strategy to find a routing path. However, such a routing path is typically not optimal. In this thesis, we propose a new location-aided routing protocol, called ant-based location-aided routing (ALR), which has two advantages: (1) ALR can find the optimal path without using flooding. In ALR, DATA packets and ACK packets mimic the behaviors of ants. Especially, ants can lay pheromone on each link along the current best path. When the amount of pheromone in a network becomes higher, the path of a DATA ant will converge to the optimal one. (2) ALR adapts well to the varying environment. Especially, ALR adopts the pheromone evaporation mechanism such that when the environment changes, the amount of pheromone on the outdated optimal path will become lower, and the path of a DATA ant will automatically converge to the new optimal one. The simulation results show that in terms of end-to-end routing delay, normalized routing overhead, and data delivery ratio, ALR outperforms existing related location-aided routing protocols.
Advisors/Committee Members: Fan-Shuo Tseng (chair), Tsung-Chuan Huang (chair), Zi-Tsan Chou (committee member), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair).

▼ Technologies and applications of biomedical signals processing become increasingly popular as integrated circuit fabrication technology and process advances, a low interference input stage in a recording circuit is very important for recording bio-signals such as electrocardiogram (ECG) and electromyogram (EMG) while the amplitude is only few millivolts or less. If the circuit cannot reject noise effectively, it is hard to amplify the bio-signal and obtain the output voltage of the recording system accurately. This thesis is focused on the measurement of several candidates of bipolar devices to be used in a differential input stage. We characterize lateral bipolar transistors in TSMC 180nm and 350nm CMOS technologies. We realized four different layout types of lateral BJT in TSMC D35 CMOS process and one type in TSMC T18 CMOS process for testing. Devices fabricated in conventional multi-project wafer runs have been measured to determine their low-frequency parameters, including transconductance, input resistance, current gain, turn-on voltage, offset and noise. It is observed that all the BJTs examined to provide a very low flicker-noise corner. The results further show that circular designs do not provide the significant advantage over using the simpler square layout. The metal may be used to cover the base area instead of using polysilicon without significantly affecting the device performance.
Advisors/Committee Members: Ko-Chi Kuo (chair), Tong-Yu Hsieh (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (chair), Robert Rieger (committee member).

► With the emerging of high-definition video, a mobile station (MS) using a single radio interface may suffer insufficient bandwidth, leading to serious mosaic or even…
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▼ With the emerging of high-definition video, a mobile station (MS) using a single radio interface may suffer insufficient bandwidth, leading to serious mosaic or even frame-frozen phenomenon. To solve the above problem, in this thesis, we propose an SVC Stream-Splitting Mechanism (SSSM) using multi-radio access technologies (Multi-RAT). In our proposed scheme, an SVC (Scalable Video Coding) streaming server divides a video stream into two sub-streams, and each sub-stream is delivered, respectively, via WiFi and LTE to an MS. When WiFi network encounters congestion, packet loss rate (PLR) will largely increase. A threshold of PLR is therefore set to divert the transmission of a certain upper SVC layers to LTE. One of the major contributions in this thesis is that we modify the DESCRIBE message of Real-time Transport Streaming Protocol (RTSP) such that the bit rate of each SVC layer can be delivered to an MS. Thus, an MS can compute the number of SVC layers to be diverted to LTE by comparing the received bit rates with the measured WiFi throughput. Additionally, since a video stream after the split into two sub-streams may produce out-of-order packets, we design a pre-buffer scheme to re-sequence the out-of-order packets by adding a common sequence number (CSN) in the Real-time Transport Protocol (RTP) header. Finally, we implement the SSSM on the Linux platform. From the experimental results, we demonstrate that the proposed SSSM with stream splitting can achieve higher throughput than that without using stream splitting. Also, the video stream received at MS can exhibit much better quality.
Advisors/Committee Members: Chung-Nan Lee (chair), Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Tsung-Chuan Huang (chair), Zi-Tsan Chou (chair).

► In this thesis, we propose a novel similarity ranking based on the distance and velocity. In addition to ranking similsrity between query user and friendâs…
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▼ In this thesis, we propose a novel similarity ranking based on the distance and velocity. In addition to ranking similsrity between query user and friendâs perfrence for the same item.We konw that the accuaacy of similarity will reduce in reality.It is because we can not know whether a friend can immediately reach the location of the inquiry and asked to do with the common interests of things. We consider friendâs distance and velocity based on similarity. According to two factors as mentioned, we designed MDBS (Modified Distance-based Similarity) algorithm. If the similarity is positive, in MDBS, we order it from large to small directly. When the similarity is negative and friends have the same distance, we propose an algorithm to modify the original order. In the algorithm, we divide friends into two categories; fixed speed and different speeds. In order to validate the algorithm, we use 20 friends as an example. In the numerical analysis, we compute the MDBS ranking based on two different situations, i.e., fixed velocity and variable velocity. From the numerical results, we found out that the MDBS ranking can be varied significantly due to different friendsâ distance and velocity. Different from the traditional similarity ranking, in this theis, we consider distance between query user and friends and different moving speed of friends,the MDBS ranking can adequately represent the real life of a social network.
Advisors/Committee Members: Ling%20Sheu%22%29&pagesize-30">Tsang-LingSheu (committee member), Tsung-Chuan Huang (chair), Chung-Nan Lee (chair), Zi-Tsan Chou (chair).

Chen, Y. (2016). A Similarity Ranking Method based on Distance and Velocity for Social Networks. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1015116-102219

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Chen Y. A Similarity Ranking Method based on Distance and Velocity for Social Networks. [Thesis]. NSYSU; 2016. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-1015116-102219

Note: this citation may be lacking information needed for this citation format:Not specified: Masters Thesis or Doctoral Dissertation